Stormchaserchuck1

We are +0.50 right now for DJFM (with 0.54 sd, 50% chance DJFM NAO comes in -0.04 to +1.04). A little less positive than I expected. In May we had a negative reading, so the warm pool later in the year has only been a part of the total measurement.

In 08-09, we started to see N. Pacific High pressure hit record levels. That was the first time that really did it in satellite era. That feature has become very strong at times in recent years, even popping over +600dm in Dec 2021. Since the arctic sea ice is melting on the Pacific side, and holding near Greenland on the Atlantic side, I do think that makes some sense.. especially since when the extreme ice melt happened in 07-12, we started seeing that N. Pacific High pressure become more frequent. It's probably not perfectly linear, but I do think since that whole western side of the Arctic circle melts in the Summer, it would flex High pressure over the north Pacific Ocean.

That's a good point. I think the correlation is sea-level height, sometimes reflected by surface SSTs. May-Sept water temps in that region has a strong correlation to the Winter NAO.. right now a custom index I made is coming at about 0.70 (+0.54 SD chance we see DJFM NAO come in around +0.70). Also, October is the only month of the year where the NAO has an opposite correlation to the Winter.. I know we have a big -NAO showing up on models for the end of Sept, but I've never really checked to see if that October opposite correlation runs into late Sept. Right now, I would say it's likely that we have a +NAO Winter.

Yeah, seriously. It seems like when the arctic ice melt stops, these massive ridges blow up. This has been the trend for many years now..

Las Vegas and Phoenix having such a consistently hot Summer does correlate to +PNA conditions in December, and sometimes it carries past then.. will be interesting with a La Nina and strong -PDO, which suggest the opposite.

I do believe that weather derivatives trading does effect the weather.. I'm probably in the minority though. Does anyone know why, probably related to arctic sea ice, a -NAO would correlate with -pna/+epo and +NAO correlates somewhat with +pna/-epo, once the cold season comes about? Another thing is sea level height.. I've connected this with subsurface water temps, especially near the thermocline. We've had a classic +NAO pattern according to sea-level height since 2011, while H5 has sometimes featured anomalous ridging near Greenland.

I contest that it is something other than +AMO and CC for why the NAO has held this correlation since 2013. It might even have to do with Summer arctic ice melt, as Greenland has held its core, and the Pacific side has gone completely iceless.. The lowest Summer arctic ice melt was 2012, then the -NAO starts connecting with dual-ridging (either over N. America or -PNA) in 2013, and carries it from that point forward, even intensifying after 2017. We see an ice melt season that is almost #2 this year, then there is this big -NAO/-PNA pattern once the cold season starts progressing on the Northern Hemisphere. It's almost like a "stop" is in place, and there is dual-ridging around Greenland at other times of the year (if someone has a more scientific reason, come forth).

Best SOI match I can find where it didn't do much all year then started going positive in the Fall is 2007.. If someone has done more in depth research in that regard, correct me if I'm wrong. 1999 waned in the Spring/Summer then strengthened again in the Fall. That's about all I could find going back to 1950. It usually starts going into a phase earlier.

We are also seeing this strong -PNA pattern for the next 15 days as the ENSO subsurface is cooling again.. 30-day SOI finally made it above 10. It seems to be re-organizing further west. This is actually quite a west-based cold pool for this time of year. Imo, that could slim the chances for warm ENSO next year. It also makes it more probable that the La Nina tries to become more west-based at the surface in the coming months. I'm thinking a more west-based subsurface cold pool/La Nina may actually weaken the chances for a -EPO Winter.. we'll have to see how it evolves in the coming time. Those +SSTAs near Japan are very +WPO. All I have going for that counter-argument is that the state of the WPO/EPO usually flips after a long, sustained phase, which have seen on both monthly and yearly scales, and this is the time period where it usually happens.

@40/70 Benchmark See how the -NAO is correlating with -PNA/+EPO. The RNA flexed here, compared to before, when the pattern becomes predominant. It's not perfect, but there is a correlation in place. https://www.meteo.psu.edu/ewall/ENSHGTAVGNH_0z/ensloopmref.html

Interesting that 13-14 was cold ENSO right in that spot where I think it has it has a cold correlation I've posted this before but anti-Strong El Nino's: Furthermore, there is not much of a PDO correlation when the highest SSTA's are over that equilateral Pacific coldest water region I contest that true El Nino's (warmest anomaly over equilatoral Pac coldest SST region) are warmer than people think, and true La Nina's are colder than people think. Furthermore, if you go all the way east-based with Nino 1+2 as the dominant region, the mid-latitude cell effect directly north of it is actually over North America, not the Pacific Ocean. Something to keep in mind going forward.. if the La Nina remains strongest in Nino 3. I think a lot of the seasonal models are looking for feedback from the -PDO, trying to make it more west-based..

I'll have to do an updated analysis this week.. I think it's coming in around 0.65-0.70 for DJFM Nice write up on here by the way. It was a good read.

October has been a wet month in the Northeast for the last 20 years

Nice +NAO signal in January with a Sept -PNA

Another thing with the -PNA roll forward, is it might support warming ENSO conditions in the late Winter/Spring:

I would definitely bet on a warm October for the CONUS. The PDO also has a strong correlation in October:

Really strong -PNA on todays 12z GEFS. +300dm, 594dm ridge in a few days. This is, not coincidentally, as ENSO subsurface is cooling again. We will have a near record breaking Aleutian ridge for March-Sept 2024, as ENSO subsurface has been near "Moderate Nina" range the whole time. Next 7 months (correlation is opposite):

It got down into the 40s here last night, and it will be close to that again tonight. The air also feels crisp, cold. I've seen a lot of lightning bugs dying. While we are still not technically in -AMO, I do agree with raindancewx that a colder pattern is coming forth, and this can't really be seen yet by global SSTs, but using cold-phase analogs may be a good way to go. I do think that if not by the Winter, then by the Spring there will be a cold pool somewhere. The problem is that the indicators are still pointing toward unfavorable indexes, but we'll see how that goes.. I have linked the +NAO, which has been near record breaking this year with -EPO, so that may be how it shows itself in future months. 18z GEFS has a pretty strong -PNA/-PDO for the next 15 days, but sometimes when things are changing the previous state will flare up. I'm also suspicious of that Aura we saw in May. It seems that every color on the color spectrum was hit.

We've definitely hit a 3 year anomaly here. 2 years ago we had 14NS in La Nina, last year we had 21NS in Strong El Nino. The longer term might have had a larger correlation that it should be.. we never did >12 NS in Moderate+ El Nino since 1948 until last year.

I'm going to get into the 40s tonight (5.5 weeks from the hottest day on average of the year)!

Fwiw, Phoenix has had 100 straight 100 degree days. The only three times it ever did it over 50 days were 1993 (76), 1989 (64), and 1935 (61) [donsutherland in the climate change forum] These are cold December's in the composite Feb 1936 lol #4 and #5 in December Edit: I see it's a progression. Well those are the top years for the record at that point. I'm sure we've had plenty of >20 days in the last few decades.

Since 2013, and more since 2019 (I would say 0.30 correlation since 2013 and 0.40 correlation since 2019), -nao has coincided with -pna/+epo and +nao has coincided with +pna/-nao. I bet you will see this tendency again this coming cold season. I only fear with the NAO, that we have exhausted all of the +NAO already this year, as it made a pretty good leap over the past few years. Sometimes it will bounce back around on the monthly scale. Dec 2021 was a good example of this.. +600dm RNA, broke the record by quite a bit, then January '22 featured the opposite pattern, despite a La Nina. A cold 10mb vortex though could amplify High pressure where the Polar Cell and mid-latitude Cell's meet. similar to how it gets warm right before a cold front passes. Put them together I guess.

It's probably because March's correlation with the PNA is near neutral While January has a pretty high correlation If MR models show a snowstorm in January and the PNA is strongly negative, I am going to be posting about it trending warmer at getting like 12 weenies on here lol

I'm all over it. +QBO/La Nina gives us about a 75% probability of having a cold 10mb for the Winter, which is actually a high percentage. I just think that strong PV downwells to amplify RNA conditions, as it has done that for the last 15 years. Of course there is some chance of a Stratosphere warming, but I am less keen on a -NAO of late, because it is not dominating the pattern like the Pacific is.

Add to it the fact that 5 of the last 6 Winter's have been +WPO And it's been super unfavorable, from 3 different uncorrelated areas.